问题
I am building ipad application in XCode 4. For that, i added some outside frameworks in my project. The code work fine in simulator but showing 24 Mach-O Linker error. I searched for this topic and get various different reasons for this error but not getting the right one. Any suggestion will be of great help.
回答1:
Most likely the library you are using has not been built for arm. For a library to work in the simulator, it must be compiled for i386 architecture. To work on the device, it must be compiled for armv architecture.
To work for both, you need what is called a "fat" binary that contains versions compiled for each of the above. If you don't have that, you will receive the linker errors.
To find out what architectures the library is compiled for, use the following command:
lipo -info mylibrary
来源：https://stackoverflow.com/questions/7497253/mach-o-linker-error